let arr = [10, 1, 22, 7, 12]
console.log(arr)
console.log(arr.sort())
console.log('---------------------------------')
console.log(arr.sort(function (a, b) {
return a - b
}))
console.log(arr.sort((a, b) => a - b))
console.log(arr.sort((a, b) => b - a))
console.log('---------------------------------')
arr = ['<ul>', '<li>xxx</li>', '<li>xxxxx</li>', '<li>xxx</li>', '</ul>']
console.log(arr.join())
console.log(arr.join(''))
console.log('---------------------------------')
arr = ['<ul>\n', ' <li>xxx</li>\n', ' <li>xxxxx</li>\n', ' <li>xxx</li>\n', '</ul>']
console.log(arr.join(''))
console.log('---------------------------------')
arr = [1,2,3,4,5,6,7,8,9]
console.log(arr.slice(2,5))
console.log(arr.slice(2))
console.log(arr.slice(-6,-3))
console.log('---------------------------------')
console.log(arr)
console.log(arr.splice(1,2))
console.log('---------------------------------')
arr = [1,2,3,4,5,6,7,8,9]
console.log(arr)
console.log(arr.splice(1,2,'a','b'))
console.log(arr)
console.log(arr.splice(1,2,['a','b']))
console.log(arr)
console.log(arr.splice(1,2,...['a','b']))
console.log(arr)
console.log('---------------------------------')
console.log(arr.splice(4,1,'x','y'))
console.log(arr)
console